Helm bobchebs



Patented Dec. 24, 1929 UNITED STATES PATENT OFFICE or new YORK,

N. Y.; SAID BOBOHEBS ABSIGNOB TO SAID STIHSON ALLOY ll'o Drawing.

This invention relates to the extraction of metallic elements in the manufacture of binary, ternary, quaternary, quintuple and more complex ferruginous alloys in which any number of the elements chromium, molybdenum and uranium may be present.

With regard to the state of the art, chromite, molybdenite (roasted) and uraninite are the sources from which chromium,

1o molybdenum and uranium are generally obtained, and rocesses have been devised wherein the minerals are smelted and reduced by means of the known deoxidizing agents, such as carbon, aluminum, silicon and the like. Use of deoxidizing reagents such as iron-ehromium-silicon alloys with, or without a proportion of a more energetic reagent, such as aluminum, has been proposed. It has also been proposed to reduce chemical compounds, such as chromic oxide and the chromates and bichromates of calcium, potassium and sodium, also mixtures of these compounds and chrome iron ore by causing them to react with metallic deoxidizing reagents.

Because of the nature of the reactions and chemical properties of the ingredients, a

necessary condition to all these proposals is the co-employment of a coalescing flux, such as lime, to form a fusible and cleansing slag.

The reduction of a mechanical mixture of lime and a refractory mineral, such as chro- -mite, molybdenite or uraninite is a difficult and prolonged undertaking which must be carried out at a high temperature (1800 C.

more or less) to provide the state of fusion essential to reaction. And when a chemical compound of chromium, molybdenum or uranium is smelted'in the presence of lime,

- not only is an expensive material being em- 4 ployed but the fusing temperature of lime must be approached before it can perform its function, and a considerable quantity of the chemical compound is vaporized and lost before the necessary temperature has been attained. a

Application flied April 14, 1924, Serial No. 706,541, and in Great Britain basicity,

April 87, ms.

The object of the invention is to avoid the difliculties of existing processes and with this in view we provide sources of the elements chromium, moiybdenum and uranium, which are in the form of oxygenous aggregates of artificial mineral matter and contain any number of the elements chromium, molybdenum and uranium. Further characteristics of these materials are their chemical and their melting-points which are below 1600 C. These reduction actions to be greatly accelerated and to be conducted at lower temperatures than is customary, and also1assist in the exclusion of metalloidal impurities.

The invention may be regarded as a. process of manufacturing ferruginous alloys of all descriptions that are low in metalloidal impurities and contain any number of the alloy elements chromium, molybdenum and uranium, which is characterized by the preparation and employment as a source, or sources from which these non-ferrous metals are obtained, of an oxygenous aggregate of artificial mineral matter that contains any number of the elements chromium, molybdenum and uranium.

The new materials may be obtained by roasting under oxidizing conditions an intimate mechanical mixture of the following (1) Metalliferous stock consisting of an ore,

concentrate, aggregate or by-product containing oxygen and chromium, molybdenum or uranium, or combinations thereof, and (2) sizable inorganic matter that has a strong basic chemical character. Oxides of calcium and magnesium are suitable stable inorganic matter, and are used in such quantity as not only to form salts with chromic molybdic or uranic acid, but also to give the product a basic character. The ingredients of the mixture, to be roasted, are crushed to the consistency of coarse sand before being employed, and, to keep them from separating during the roasting treatment, it is advisable to bind them new materials enable stood that the .ever, for illustrative together with anaqueous solution of a carbonate or an hydroxide of an alkali metal or an alkaline earth metal, such as sodium carbonate or caustic soda. A stream of fresh air has been found to be a suitable source from which to obtain oxygen required to oxygenate the roasting mixtures; and, to prevent the mixtures" from agglomerating at about 1200 C., which condition would curtail the'extent of oxygenation, the basic inorganic matter employed is preferably of a refractory nature, such as lime.

Because it is in the greatest demand at this time, the production of a chromium-containing, meta liferous material, in accordance with the invention, will now be described; it being understood that no limitation is implied to the procedure or to the employment of the particular materials that are mentioned for illustrative purposes :A binding-solution composed of water and soda-ash is used to slake suificient burnt lime to produce a mixture having the consistency of thin paste. Into this paste chrome-iron ore is mixed or kneaded employing a quantity exceeding that of burnt lime. This mixture is then dried and crushed into particles about the size of a buckshot, in which form it is roasted (at a temperature of about 1100 (1.), in an oven f t e type that provides an abundance of free oxygen, or fresh airto the roasting mixture. By these means and in this manner ferrous oxide (FeO) is transformed into ferric oxide (Fe O,) and salts of chromic anhydride I (C10,) are formed (CaCrO and N a CrO.).

e quantity of lime emdploy'ed is, at least, suflicient to give the pro uct a basic chemical character, and is preferably-sufficient to ensure that when the roduct is used in reduction operations, aci ic oxides that may be formed during such operations will be speedily and retentively incorporated into the slag, without requiring an independent flux for this purfiose. As wi be recognized the silicacontent of various grades of ores and lime available in the market, makes it necessary, as occasion demands, to alter the ratios in which the components are employed in the production of the new materials. Therefore, it will be underscope of .the invention, as claimed, includes the use and employment of the in dients in an and all proportions that ren er the materia s suitable as a source on which to recover metallic chromium, molybdenum or uranium.

e composition of the mixture to be roasted is preferably adjusted to accord with the deoxidizing reagent to be employed; howpurposes and without Lmpslying limitation we will disclose the detai of making a metalliferous material which reacted satisfactorily under the influence of open-hearth furnace tem ratures, with a metallic silicide which approximately as follows z-carbon 0.6%; silicon iron 25%; chromium The binding-agent consisted of 850 kgs. of water in which 160 kgs. of soda ash had been dissolved. 1200 kgs. of quick lime were slaked in this binding solution after which about 1300 kgs. of washed Baluchistan chromite was added and thoroughly mixed in the paste. After bein dried the mixture was crushed and roasted at a temperature approximating 1050 de ees C. Metal iferous materials used, according to the invention, as sources from which to obtain alloy elements enable ferruginous alloys, containing one or more of the elements chromium, molybdenum or uranium, to be produced by a reduction action, or it may be y reduction and alloying actions, wherein difliculties usually encountered are avoided. For instance, reactions may be completed in a fraction of the time required when chromite and lime are emplo ed merely in mechanical admixture, and as the meltingpoints of the new materials are below 1600 C. (whereas the melting-point of a mechanical mixture of chromite and lime is approximately 1800 C.) a substantial saving is effected in the amount of heat to be applied. It will be understood that what is meant b reduction action is an operation in which metals are extracted from a furnace charge containing oxygenous aggregates of the metals by means of deoxidizlng reaction; and by reduction and alloying actions is meant an operation of the class wherein the reduction reaction is caused to occur above a ferrous bath, as of carbon or alloy steel, whereby the extracted metal sinks into and belcorrliles dissolved in the underlying metal- In such reactions there may be employed, in conjunction with the new materials, any of the known metallic and metalloidal reducing agents, Whether they be used singly or in combination of two or more, but it is preferable to employ those of the substantlally carbon-free class in order to prevent amount of carbon from be-' an unnecessar coming absorged by, and chem cally combined with the extracted metal, or components of the metal-bath. For the purpose of economy silicon-containing reducing agents are generally employed, a convenient form ing an iron-silicon metal which also contains the alloy element to be extracted-for example an iron-chromium-silicon alloy. Quaternary and more complex alloys are easily produced by employin a deoxidizing reagent such as iron-nickel-silicon alloy, with for example, a chromium-containing metalliferous material.

As an example of the application of the new metalliferous materials in a reduction operation, the following adopted :,An intimate procedure may be mixture of 'the new.

slag becomes viscous, whereupon the tem erelectric, reverberatory or other suitable furnace, or a reaction chamber, or upon nonoxidizing, non-metallic matter protecting a bath of suitably purified carbon or alloy steel. Towards the end of the reaction the ature may beincreased and a liquefying ux, such as'tluorspar, or an oxide-of manganese or titanium, may be added to hasten and. comnlete the demeta'lization of the slag. With minor modifications the new materials act as unusually efiicient puri ing agents because of the readiness with w 1c h they oxidize and. cause the removal of OX1- dable impurities from an underlying-metalbath but their use as purifying agents forms the subject-matter of our specification Serial No. 706,540, and forms no part of the present invention.

It is to be understood that the metalliferous materials are advantageously employed in the production of a great diversity of ferruginous alloys containing chromium, mt'ilybdenum or uranium, as may be illustrated by mentioning term-molybdenum in which iron is an undesired component; also restless iron and chrome steels in which iron is intentionally the preponderating component; also acid resisting metals that contain three or more elements in addition to iron.

By the generic term oxygenous aggregate of artificial mineral matter, as used in this specification and appendant claims, we mean oxygenous aggregates that are very largely or substantially composed of artificial mineral matter but not to the exclusion of small quantities of impurities, such as alumi mites, silicates and the like, that are natural mineral matter, or minerals. The adjective mineral is intendcd to eon\ey.:pertaining to, consist-ingot, or resembling minerals. The adjective ferruginous" is intended to convey :carrying, or containing iron (Iron & Steel, 'liemann, 1919, page 172).

\Vhat we claim is:-

LA process of manufacturing ferruginous alloys of all classes and descriptions that contain at least one of the metals chromium, molybdenum and uranium, which comprehends producing an artificial, superoxygenated metalliferouscommodity that has basic chemical properties and yields at least one of the metals chromium, molybdenum and uranium, and directly metallifying said artificial commodity.

2. A process of manufacturing ferruginous alloys, which comprehends producing and thereafter ektracting metal directly from an artificial, superoxygenated metalliferous,

basic commodit that yields at least one of the elements 0 romium, molybdenum and uranium, which is situated above a bath of metal comprising the element iron.

3. A process of producing ferruginous alloys, which comprehends producing an artificial superoxygenated metalliferous commodity that yields at least one of the elements chromium, molybdenum and uranium, that contains uncombined CaO and melts at a temperature below 1600 0., and heating said commodity in the presence of a reducing agent to directly metallify it. i v

4. A process of manufacturing ferruginous alloys, which comprehends mixing any number of ores and by-products, containing any number of the elements chromium, modybdenum and uranium, with calcareousmatter; then heating the mixture in the presence of free oxygen and thereafter smelting the basic, oxidated product in the presence of a reducing agent. 7

5. A process of manufacturing ferruginous alloys, which comprehends mixing beneficiated metalliferous mattercontaining at least one of the elements chromium, molybde num and uranium-with strongly basic inorganic matter; incorporating therewith a basic binding agent; roasting the mixture in the presence of free oxygen and thereafter metallityin directly the oxidated product.

6. process of manufacturing ferruginous alloys, which comprehends forming a thin paste by slaking burntlime in an aqueous solution of soda ash; mixing metalliferous inaterialcontaining at least one of the elements chromium, molybdenum and uranium-into the paste; drying and crushing the mixture; roasting the mixture in the presence of an abundance of oxygen, and thereafter directly metallifying the product.

7. A process of manufacturing ferruginous alloys which comprehends mixing a quantity of metalliferous matter-containing at least one of the elements chromium, molybdenum and uraniumwith'basic inorganic matter, the latter being employed in excess of the amount required to form salts with the total quantity of metallic acids that can be produced from the metalliferous material; then roasting the mixture in an abundance of free oxygen, and thereafter reducing the product tometal. I

8. In the production of the ferruginous alloys and by a process, the step of mixing metalliferous mattercontaining-any number of the elements chromium, molybdenum and uranium-with basic inorganic matter having a refractory nature and a meltingpoint about 1600 G.; whereby the mixture is prevented from agglomerating, whilst being heated, in the presence of oxygen, before salts of. acids of any number of the elements chromium. molybdenum and uranium, are formed.

9. In the production of the ferruginous alloys and by e process, the step of artificielly giving basic chemical properties to matter that yields at least one of the metals chromium, molybdenum and uranium, which comprehends roasting the metalliferous matter in the presence of abundances of lime and free oxygen, at a temperature which is below L W. BORCHERS.

R. W. STIMSON. 

